IJRMET Vol. 6, IssuE 2, May - ocT 2016 ISSN : 2249-5762 (Online) | ISSN : 2249-5770 (Print)

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Geometrical Study of Fins Using ANSYS as a Tool1Bharti Sharma, 2Dr. Satyendra Singh, 3Vinod Kumar, 4Ravi Kumar

1,2,3,4Dept. of Mechanical Engineering, BTKIT Dwarahat, Uttarakhand, India

AbstractThe purpose of this study is firstly to give an overview of the Fins and description of recent improvement of fin geometries to increase the heat transfer rate. The objective of this investigation is to improve the performance of the fins using different geometry Circular, Rectangular, Trapezoidal and Helical of the fins without and with the holes. Through ANSYS simulations for fins in both conditions with and without holes, this study is trying to analyses the heat transfer rate in the fins. Current efforts focus on increasing their efficiency. In this project, focus on exploring the way to increasing the fin performance with and without holes.

KeywordsANSYS TRANSIENT THERMAL 14.0, Fins (Circular, Rectangular, Trapezoidal and Helical) with Holes and Without Holes, Natural Convection, Heat Flux and Heat Transfer Rate.

I. IntroductionFor heat transfer using the extended surfaces is very important in many fields including industries, heat exchangers, power plant sectors, engine cooling, transformers etc. Extended surfaces are known as fins and this is used to increase heat transfer rate. A large number of research analyses have been carried out the heat transfer rate during the recent years. Sharma et al. [9] present theresults of computational numerical analysis of air flow and heat transfer in three different pin fins. A numerical study using Ansys fluent to find the optimum pin shape based on minimum pressure drop and maximizing the heat transfer. They analyzed that the Drop shaped fin having better thermal efficiency and effectiveness.Kushwaha et al. [7] in this paper deals with the comparative study of heat sink having fins of various profiles namely Rectangular, Trapezoidal and Parabolic. In this paper geometry generated by UNI- Graphics NX-6 and result analyzed Trapezoidal have a maximum heat transfer by FLUENT.Gawai et al. [4] presented the experimental investigation of Brass and Aluminum Pin fin by forced convection they found the Heat transfer coefficient and efficiency of aluminum is greater than brass. Chen et al. [2]Performed analysis convective heat transfer and pressure loss in rectangular ducts with drop shaped pin fin by cross flow air and they analyzed the result is Heat transfer is of drop shaped pin fin is higher than circular pin fin. Vohra et al. [12] performed CFD analysis of cylindrical pin with Trapezoidal fin Heat sink using ANSYS fluent 14.0. Circular pin fin is more pressure drop than elliptical pin fin heat sink. Richard and Agilan.H [8] performed experimental analysis of Heat Transfer enhancement using fins in pin fin apparatus by forced convection. Aluminum, Brass and Copper Pin fin used in this experiment and Copper have a higher thermal conductivity then others. Sukumar et al. [10] areanalyzed and modeling of heat sink with rectangular fins having through holes they using PRO-E WILDFIRE 5 for geometry modeling ofrectangular fins continuous, interrupted and with holes, and the result shows better performance of the interrupted fins through holes than others. Swain et al. [11] studying a comparative study on Heat Transfer in straight triangular fin and porous pin fin under Natural convection after the comparison they conclude the Porous pin fin is more efficient than straight and triangular pin fin.Jadaun et al. [5]they are performed thermal Analysis of optimized porous fin on various profiles in MATLAB and found the value

of Darcy number increased then fin efficiency decreased but fin effectiveness increased in this investigation.Kumar and Bartaria [6]performed CFD analysis of an Elliptical pin fin heat sink using Ansys Fluent v12.1 using Elliptical pin fin in different minor axis 1.5mm, 2mm and 2.5mm. In all computational fluid dynamic analysis, result found 2mm minor axis having better thermal resistance and pressure drop.Dhanawade et al. [3]aluminum square and circular perforated fin array is used to thermal analysis by forced convection and they conclude that square perforated fin array is more efficient than circular. Bhunte and Kumbhare [1] investigate the optimum porous pin fin parameter for forced convection heat transfer through Rectangular channel and in this paper used porous Pin fin with 20,30 and 40 Pore density (PPI) and cold fluid is air and water and all investigation is performed in ANSYS FLUENT. They conclude in the case of air the overall heat transfer efficiency decreases with the increasing PPI 20 to 40.

II. Geometrical Description The geometry created for analysis having different types of shapes, Fins with holes and without holes. Geometry is generated through Solid works in IGES format. This file is import in ANSYS for analysis. For analysis used a dimension in tabular form.

Table 1: Geometry DetailsPhysical parameters Values Base plate dimension (cm) 12*12Length of fins (cm) 10 Diameter of Circular and Helical fins (cm) 2Rectangular fin dimension (cm) 2*2

Trapezoidal fin dimension (cm) 2.5*2.5 (base), 1.5*1.5 (tip)

No. of turns in Helical fin 5Diameter of holes 1.5Material Brass

III. Meshing DetailsTable 2: Mesh Setting (Fins Without Holes)Physical properties ValuesPhysics preference CFDSolver preference Transient ThermalSmoothing MediumTransition FastGrowth rate 1.2Transition ratio 0.272

Nodes

Circular 2625Rectangular 2655Helical 3888Trapezoidal 3072

Elements

Circular 956Rectangular 1018Helical 1922Trapezoidal 1554

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Table 3: Mesh Setting (Fins With Holes)Physical properties ValuesPhysics preference CFDSolver preference Transient ThermalSmoothing MediumTransition FastGrowth rate 1.2Transition ratio 0.272

Nodes

Circular 3097Rectangular 3501Helical 6271Trapezoidal 4062

Elements

Circular 1516Rectangular 1165Helical 3116Trapezoidal 2116

IV. ResultThe Heat transfer and flow characteristics of a fins can be visualized of the contour diagrams of Heat flux and Temperature distribution and values of Temperature, and the graphs of Heat Flux and Time which have been plotted ANSYS Transient Thermal 14.0.

A. Total Heat Flux Contour Without Holes

Fig. 1(a): Rectangular fin Fig. 1(b): Trapezoidal fin

Fig. 1(c): Circular fin Fig. 1(d): Helicalfin

B. Temperature Contour Without Holes

Fig. 2(a): Rectangular fin Fig. 2(b): Trapezoidal fin

Fig. 2(c): Circular fin Fig. 2(d): Helicalfin

C. Total Heat Flux Contour With Holes

Fig. 3(a): Rectangular fin Fig. 3(b): Trapezoidal fin

Fig. 3(c): Circular fin Fig. 3(d): Helicalfin

D. Temperature Contour With Holes

Fig. 4(a): Rectangular fin Fig. 4(b): Trapezoidal fin

Fig. 4(c): Circular fin Fig. 4(d): HelicalfinThe results shown in tabular forms in both condition with holes and without holes:

IJRMET Vol. 6, IssuE 2, May - ocT 2016 ISSN : 2249-5762 (Online) | ISSN : 2249-5770 (Print)

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Table 4: Heat Flux and Heat Transfer Coefficient (Without Holes)Fins Without Holes Circular Rectangular Trapezoidal Helical

Maximum temperature ( ͦ C)

100.06 100.04 100.01 100.05

Minimum temperature ( ͦ C)

82.445 82.668 89.962 22

Heat flux (W/m2) 4.387e5 4.744e5 3.580e5 1.1533e6

Heat Transfer Coefficient (W/m2 ͦ C)

5620.03 6078.93 4589.53 14776.42

Table 5: Heat Flux and Heat Transfer Coefficient (With Holes)Fins without holes Circular Rectangular Trapezoidal Helical

Maximum temperature (ͦ C)

100.01 100.04 100.01 100.01

Minimum temperature (ͦ C)

81.333 81.649 89.452 22

Heat flux (W/m2 ) 6.9005e5 5.8424e5 3.216e5 1.9134e5

Heat transfer coefficient (W/m2 ͦ C)

8835.46 7486.41 4122.54 1245227.62

V. ConclusionThe present work is successfully carried out by comparing various shapes of fins with holes and without holes. The four types of shapes are chosen for the comparison i.e. circular, rectangular, helical and trapezoidal. Analysis has been carried out in ANSYS 14.0 Transient Thermal by changing shape of fins with holes and without holes.

The fins without holes are compared for different chosen • shapes. Comparing this, it is found that helical fin gives better result because it has maximum surface area which provides maximum heat transfer.The same process is carried out for with holes condition. In • this process also, helical fin provides better results among other fins.It is found that geometry of Helical Fins with hole have a better • Heat transfer rate as compared to the fins without holes.

References[1] Bhunte, S.V., Kumbhare, S.,“Investigation of optimum

porous pin fin parameter for forced convection Heat transfer through Rectangular channel part- 1”, Emerging Technology and Advanced Engineering , Vol. 4, Issue 8, pp. 2250-2459, 2014.

[2] Chen, Z., Li, Q. , Meier, D., Warnecke, H. J.,“Convective heat transfer and pressure loss in rectangular ducts with drop shaped pin fins”, Heat and Mass Transfer, Vol. 33, Issue 219-224, 1997.

[3] Dhanwade,K.H., Sunnapwar, V.K., Dhanwade H. S., “Thermal analysis of square and circular perforated fin arrays by Forced convection”, Current engineering and technology,

Vol. 2, Issue 2277- 4106, 2014.[4] Gawai, U.S., Mathew, V.K., Murtuja, S.D.,“Experimental

Investigation of Heat transfer by pin fin”, Engineering and Innovative Technology, Vol. 2, Issue 7, 2013,

[5] Jadaun, A. P. S.,Arya, A.,“Thermal analysis of optimized Porous Fin in various profile”, Thermal analysis, vol. 3, Issue 3, pp. 2321-0613, 2015.

[6] Kumar, V., Bartaria, V.N.,“CFD Analysis of an Elliptical pin fin heat sink using Ansys Fluent v12.0, Modern Engineering, Vol. 3, Issue 2, pp. 1115-1122, 2013.

[7] Kushwaha, A.S., Kirar, R.,“Comparative study of Rectangular, Trapezoidal and Parabolic shaped finned Heat sink”, Mechanical and Civil engineering, Vol. 5, Issue 6, 2013.

[8] Richard, T.L., Agilan H.,“Experimental analysis of Heat Transfer enhancement using fins in pin fin apparatus”, Core engineering and management, Vol. 1, Issue 2.

[9] Sharma, S. K., Sharma, V.,“Maximizing the Heat Transfer through Fins using CFD as a Tool”, Recent advances in Mechanical Engineering, Vol. 2, Issue 3, 2013.

[10] Sukumar, R.S., Sriharsa, G., Arun, S.B., Kumar P. D., Naidu, Ch. S.,“ Modelling and Analysis of Heat sink with Rectangular fins having through holes”, Thermal analysis, Vol. 3, Issue 2, pp. 1557-1561, 2013.

[11] Swain, J., Kumar, G., Singh, D., Sen, P. K.,Bohidar, S. K.,“ A Comparative study on Heat Transfer in Straight Triangular Fin and Porous Pin Fin under Natural Convection” , Thermal Analysis, Vol.2, Issue 11, pp. 611-619, 2014.

[12] Vohra, I., Azim, A.M., Saxena, B.B.,“CFD analysis of Cylindrical pin with Trapezoidal fin Heat sink using ANSYS fluent 14.0 ”, Emerging technology and Advance technology, Vol. 4, Issue 5, 2014.